Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
KAIST Institute for NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
ACS Appl Mater Interfaces. 2017 Nov 22;9(46):40868-40877. doi: 10.1021/acsami.7b13298. Epub 2017 Nov 9.
Demand of adhesives that are strong but ultrathin with high flexibility, optical transparency, and long-term stability has been rapidly growing recently. Here, we suggest a thermally curable, "sticky" nanoadhesive with outstanding adhesion strength accomplished by single-side deposition of the nanoadhesive on arbitrary substrates. The sticky nanoadhesive is composed of an ionic copolymer film generated from two acrylate monomers with tertiary amine and alkyl halide functionalities, formed by a solvent-free method, initiated chemical vapor deposition (iCVD). Because of the low glass transition temperature (T) of the copolymer (-9 °C), the ionic copolymer shows a viscoelastic behavior that makes the adhesive attachable to various substrates, regardless of the substrate materials. Moreover, the copolymer film is thermally curable via a cross-linking reaction between the alkyl halide and tertiary amine functionalities, which substantially increased the adhesion strength of the 500 nm thick nanoadhesive greater than 25 N/25 mm within 5 min of curing at 120 °C. The adhesive thickness can further be reduced to 50 nm to achieve greater than 35 N/25 mm within 30 min at 120 °C. The nanoadhesive layer can form uniform adhesion in a large area substrate (up to 130 × 100 mm) with the deposition of the adhesive only on one side of the substrates to be laminated. Because of its ultrathin nature, the nanoadhesive is also optically transparent as well as highly flexible, which will play a critical role in fabrication and the lamination of future flexible/wearable devices.
最近，人们对高强度、超薄、高柔韧性、光学透明性和长期稳定性的胶粘剂的需求迅速增长。在这里，我们提出了一种热固型“粘性”纳米胶粘剂，它通过在任意基底的单侧沉积纳米胶粘剂来实现优异的粘附强度。粘性纳米胶粘剂由具有叔胺和烷基卤官能团的两种丙烯酸盐单体形成的离子共聚物薄膜组成，通过无溶剂方法、引发化学气相沉积（iCVD）形成。由于共聚物的低玻璃化转变温度（-9°C），离子共聚物表现出粘弹性行为，使胶粘剂能够附着在各种基底上，而与基底材料无关。此外，共聚物薄膜可以通过烷基卤和叔胺官能团之间的交联反应进行热固化，这大大提高了 500nm 厚纳米胶粘剂的粘附强度，在 120°C 下固化 5 分钟内超过 25N/25mm。通过将胶粘剂的厚度进一步降低到 50nm，可以在 120°C 下 30 分钟内实现超过 35N/25mm 的粘附强度。纳米胶粘剂层可以在大面积基底（最大 130×100mm）上形成均匀的粘附力，只需在要层压的基底的单侧沉积胶粘剂即可。由于其超薄的特性，纳米胶粘剂也具有光学透明性和高柔韧性，这将在未来的柔性/可穿戴设备的制造和层压中发挥关键作用。
